#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

int main() {
    int a, b, c, d, max;
    scanf("%d %d %d %d", &a, &b, &c, &d);
    max = a;
    max = max > b ? max : b;
    max = max > c ? max : c;
    max = max > d ? max : d;
    printf("%d", max);
    return 0;
}
